> It's closer to your neighbour selling you the rights to park in their garden, then you selling those rights to someone else. Far from a criminal, arrestable offence, so their point on the broad-brush of being "illegal" stands.
That's a good analogy, but perhaps not for the reason you think. In many situations where you acquire property rights from an owner, there are clauses which restrict or limit sub-leasing to a third party, or using the land for commercial gain. If I was doing what you are describing, I would want to read the lease or agreement very carefully to see whether I am allowed to do that.
Again, I think the developer acted in good faith, but it seems a bit naive to resell something for profit (no matter how small) without seeking legal advice, or at very least reading the T&Cs. We also cannot accuse the government of setting arbitrary restrictions - ticket touting is a problem, even if the government probably could have done more to make it easier for people to buy tickets legitimately.